Conventionally, as reflecting articles such as a housing, a reflector or an extension in an automobile lamp, a lighting apparatus in a household electrical appliance or the like, a metallic product (metal plate), a product in which a thermosetting resin represented by bulk molding compound (BMC) or sheet molding compound (SMC) is metal plated or vapor deposited or coated with a metal film, has been used. The metallic reflecting article is inferior in processability, heavy and not easy handling. On the other hand, the reflector in which a thermosetting resin is metal plate processed or vapor deposited with a metal film has excellent properties in heat resistance, rigidity,. dimensional stability, etc., but it has problems that the molding cycle is long, that a flash is formed at the molding, or that a monomer may vaporize to worsen the working environment. For that reason, a thermoplastic resin vapor deposited thereon a metal film which has not such problems and is excellent in productivity has become a major trend, accompanied by improvement of functionality and diversification of design of these light-reflecting articles.
As such a production method of the light-reflecting article, a method to treat the portion to be light-reflecting surface with a primer to impart surface smoothness, then to vapor deposit a metal, and further, to coat with a top coat, can be mentioned. However, the above-mentioned conventional method to coat a primer is not preferable for environment since organic solvent is used for the primer, and further, there was a problem that the metal plate processing or the vapor deposition is expensive and the total cost is also high since it takes a long time to evaporate the above-mentioned organic solvent and to cure the coated film. Accordingly, a thermoplastic resin composition for light-reflecting article capable of being directly vapor deposited which can be processed in a low cost without pretreatment has been demanded.
In order to respond to the requirement for such a thermoplastic resin composition for light-reflecting article, in the patent reference 1, a resin composition in which polycarbonate and a fine powdered filler are compounded to polybutylene terephthalate is proposed. And, in the patent reference 2, a method in which a fine powdered filler is used as a reinforcing material to a resin composition comprising a polyalkylene terephthalate-based resin and a silicone oil, is proposed. In addition, in the patent reference 3, a reflecting article in which a reflecting metal layer is provided on polybutylene terephthalate or copolyester containing a finely powered filler.
However, in case where the resin composition described in the patent reference 1 is used, releasability is not good and molding cycle is not short, in addition, the brightness feeling decreases when the light-reflecting article, on part or whole surface of which a vapor deposited metal film is formed, is exposed to a high temperature. And, in case where the resin composition described in the patent reference 2 is used, its rigidity is insufficient, and when a primer is not used to the surface of the molded article, the brightness feeling of the light-reflecting article, on part or whole surface of which a deposited metal layer is formed, is often unsatisfactory. In the reflecting article described in the patent reference 3, when a directly vapor deposited metal film is formed, the brightness feeling is insufficient.
Patent reference 1: JP-A-1999-101905
Patent reference 2: JP-A-1999-61382
Patent reference 3: Specification of U.S. Pat. No. 4,429,004